The time it takes for a dream to develop from being in SP is difficult to say with any certainty. It will most likely depend on how sleepy you are. I have heard a number of people saying that they have experienced twitching I believe it is normal. If it becomes a problem I would try tensing my entire body and holding for a few seconds before starting relaxation.
Personally I am doubtful that dreaming or lucid dreaming could make you feel tired. There are another few possibilities I can think of, such as, when you are sleeping. I found that when I started getting up earlier and going to sleep earlier, still getting the same amount of sleep as before, I felt tired. If you have an illness of some kind, like a cold or whatever, that can also make you feel like you need more sleep.
Personally I would avoid switching techniques so quickly, I don’t think it would give you a fair evaluation. If you are finding it is frustrating you, then I can understand, but I feel it would work better if you are fully focused on the technique you are trying, rather than trying to decide at the time, if it is working.
This is a split topic, the next part is First Steps to WILD part IV (Basic WILD Q&A). 